This invention relates to flashlamp assemlbies and, mor particularly, to a device comprising an array of percussively ignitable flashlamps with a mechanism for permitting selective firing of the flashlamps in response to successive actuation. A particular embodiment of interest is that of a signal device intended for hand operation.
A copending application Ser. No. 696,107, filed concurrently herewith and assigned to the present asignee, describes an improved signal device of the type which generates intense flashes of light and provides the advantages of being compact, light weight, safe, relatively inexpensive, and not requiring batteries or an electric cord connection for operation. More specificially, a hand held signal device is described comprising a plurality of percussively ignitable flashlamps mounted on a support member along with a plurality of preenergized striker springs, each releasable to fire a respective flashlamp. In order to selectively fire the eight lamps in sequence, a slide member having a projecting trip wire is retained in a channel parallel to the row of flashlamps and in alignment with the striker springs, which in the cocked condition project beyond the periphery of the channel. To operate the device, a user grasps the periphery of the unit enclosure with one or two hands, faces the lamps in the direction of the intended viewer, and with is thumb slides the movable member along the channel to trip the strikers.
Although providing a relatively simple and inexpensive signal device, the unit described in the aforementioned copending application generally requies two hands for holding the device and firing the lamps, and is somewhat awkward for single-handed operation. In certain emergency situations, such as a person handling a boat in distress or floating in the water by the aid of a life-vest and clutching an overturned boat, it is particularly advantageous to have a signal device which may be very conveniently operated with one hand.
Another copending application Ser. No. 695,991, filed concurrently herewith and assigned to the present assignee, describes a signal device particularly adapted for single-handed operation. In this instance, firing of the lamps is provided by a selective actuating mechanism comprising a spring-loaded ratchet bar retained in a longitudinal channel in the support member which is located parallel to the row of flashlamps. A slidable member is also retained in the channel in engageable contact with the ratchet bar. Means is provided on the slidable member for sequentially releasing the preenergized striker springs to fire respective ones of the flashlamps in response to successive hand actuation of the ratchet bar and the resulting indexing of the slidable member engaged therewith along the channel.
In a preferred embodiment, light-shield partitions are disposed between respective pairs of the flashlamps to prevent sympathetic ignition, and a cover having at least one transparent side is fixed to the support member so as to enclose the assembly. The slidable member comprises a folded flat spring having a first tang for engaging one of the teeth on the ratchet bar and a second tang for engaging a surface of the support member channel to thereby prevent the slidable member from reversing direction following indexing thereof. The release means comprises a sloping trip wire projecting from the slidable member and disposed so that its path of travel is aligned with projecting portions of the striker springs. A push button is attached to one end of the ratchet bar and is externally accessible for indexing by hand to operate the signal device. Accordingly, a manually operated signal device is provided which can be fired with a single hand very comfortably using a relatively inexpensive trigger device.
One disadvantage of the firing mechanism described in the above referenced application Ser. No. 695,991, however, is the need for a preenergized striker spring for each lamp in the array. Thus, in an array of 16 lamps, for example, 16 firing springs are required. From a manufacturing point of view these springs add to the cost of th device both from a material and assembly point of view. Another disadvantage of the lamp firing springs is that they decrease the packing density of lamps insertable in the array package. This is so because each spring requires approximately 0.0625 inch of linear space along the lamp base. Thus, for instance, in a 10-lamp linear array the package has to be increased 0.625 inches in length to accommodate the lamp springs. A further disadvantage of individual lamp springs in that a portion of the light emitted from the lamps was masked by the spring wires. Further, usage of the lamp springs requires lamps to be offset with respect to the slider trip wires, which in turn necessitates offsetting of the lamps in the finished array package if a minimum depth dimension is desired. Such a geometry can place one wall of each lamp in a very close proximity to the package wall, at which point undesirable heating can occur during lamp flashing. Yet another disadvantage of the many springs needed in the array described is that their usage visually detracts from the aesthetic appearance of the array package.